Circuit board



FIG. 1 is a front view of a circuit board showing my new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

Throughout the drawings, the dash-dash broken lines are for the purposeof illustrating environment only and form no part of the claimed design.

CLAIM The ornamental design for a circuit board, as shown and described.